The present invention relates to a device for feeding revenue stamps on a cigarette packing machine.
On cigarette packing machines, revenue stamps are usually affixed to the finished packets coming off a wrapping wheel, which stamps are either withdrawn, by means of a feeding device, from the bottom of a stack, or cut successively off a continuous strip.
On known feeding devices, each revenue stamp is picked up by a roller and fed by the same to the top of a vertical guide defined by a number of pairs of parallel rollers. As it moves down the said guide, each stamp is gummed on one side, by means of gumming devices, and then fed axially into a pocket having a lateral withdrawal opening on the gumfree side of the stamp. Each stamp is held by suction inside the said pocket and withdrawn from the same, through the said lateral opening, by means of a fork grip. The said grip comprises arms having suction means for cooperating with the gumfree side of the stamp housed inside the said pocket, and designed to travel parallel with the axis of the said lateral opening, for extracting the stamp from the said pocket and transferring it, via rotation of the said fork about an axis parallel with the axis of the said lateral opening, to an affixing location along the route travelled by the finished packets coming off the said wrapping wheel.
At the said affixing location, each packet coming off the said wrapping wheel travels through the arms on the said fork grip and, cooperating with the gummed side of the stamp stretched between the arms on the grip, causes the stamp to be ripped off the arms and affixed to one end of the packet.
One of the major drawbacks on known revenue stamp feeding devices of the aforementioned type is that, as they travel down the said roller guide, the stamps tend to slide laterally into a skew position. Consequently, in addition to the receiving pocket at the bottom end of the roller guide having to be designed wider than the stamp, for preventing possible jamming, the stamp may be fed crookedly into the pocket, thus resulting in it being withdrawn, not perfectly straight, by the fork grip, and affixed crookedly onto the packet.
A further drawback on known feeding devices of the aforementioned type is that the gumming devices are located along the said roller guide, i.e. over the receiving pocket. Consequently, any gum dripping from the gumming devices falls straight onto the receiving pocket, which must therefore be cleaned frequently for preventing the stamps from sticking to the pocket and thus stopping the machine.